Diplomat Robert ‘Woody’ Johnson said the US President – due to visit the UK next week – wants a “quick deal” to drastically increase trans-Atlantic trade between the “special relationship” allies after Britain quits the EU.
“The President thinks it’s time to go,” he said, adding: “The sky’s the limit.”
The offer, which could slash the prices of US imports for British consumers and boost job creation on both sides of the Atlantic, was hailed as a massive vote of confidence in the UK’s future outside the European bloc.
And it came as the Prime Minister edged close to an EU departure deal with Brussels by winning Cabinet backing for her Brexit plans.
Aides said a crunch meeting of the full Cabinet at Chequers, Mrs May’s countryside retreat, saw “constructive and positive” discussions after months of wrangling between ministers.
Mr Johnson laid bare White House’s enthusiasm for accelerating talks on a UK-US trade in an exclusive interview with the Daily Express ahead of Mr Trump’s long-awaited first official UK visit since becoming president.
He is due to meet the Queen at Windsor Castle, hold talks with Mrs May at Chequers and will be welcomed with a back-tie banquet at Blenheim Palace, the birthplace and ancestral home of Winston Churchill.
Speaking at the new US Embassy complex in south London, Mr Johnson confirmed that “zero tariffs” on all trade between Britain and the UK could be the starting point for negotiations on a post-Brexit deal between the two allies.
“I think it would be bold and why not start off with that premise,” he said.
“The President will put his full energy behind a quick deal.”
Mr Johnson said the president instinctively wanted to seize the moment to agree a post-Brexit trade deal with the UK as soon as possible.
“As an American you want to get on with it and make a deal quickly so business people can organise around this.
“We would encourage movement. The President thinks it’s time to go,” the London-based ambassador said.
In his interview, Mr Johnson was also optimistic about Britain’s prospects outside the EU.
“The sky’s the limit. As an independent nation you will be agile, nimble, attract capital. You’ve got so much capability here. It will be nice to see you go at full tilt,” he said.
“It will show the strength of the Special Relationship we have.
“We’ve got to remember that Britain is a valued partner, the likes of which we don’t have anywhere else.”
He added: “You’ve got something really special here – the language, the culture, history, legal system, the institutions that are the envy of the world. When you stand up on your own it will be something to watch.”
Mr Johnson also took a swipe at Brussels for resisting Mrs May’s offer of full security cooperation between the UK and the EU after Brexit.
“It doesn’t make sense,” the ambassador said. “It’s illogical, particularly over something like terrorism. You have got to share.” He added: “I don’t know what their motivation is.”
Brexit campaigners were delighted by the ambassador’s positive remarks.
Tory MP Nigel Evans said: “This is brilliant news. We already have an excellent trade relationship with the US even before we do a trade deal.
“The special relationship between the UK and the US would be greatly enhanced by zero tariffs. It would be the best start for Brexit and a huge boost for jobs on both sides of the Atlantic.”
And the accelerating moves towards a trade deal came as the US and China slapped tit-for-tat duties worth £26billion on each other goods last night.
Beijing accused the Trump administration of triggering the “largest-scale trade war” following the exchange.
Chinese Premier Li Keqiang said: “Trade war is never a solution.”
He added: “China would never start a trade war but if any party resorts to an increase of tariffs then China will take measures in response to protect development interests.”
Mr Trump hit back by suggesting the US could target around £380billion-worth of Chinese imports.
A Chinese state media report accused the US government of acting like “a gang of hoodlums”.
“In effect, the Trump administration is behaving like a gang of hoodlums with its shakedown of other countries, particularly China,” the state-run China Daily newspaper said.
“It’s unruliness looks set to have a profoundly damaging impact on the global economic landscape in the coming decades, unless countries stand together to oppose it.”